It is well known that the pay-per-view market in the cable television industry is limited to cable systems with highly advanced technology (addressable circuitry). Pay-per-view service occurs when a particular event is presented by a cable system and the customers of the system pay a premium to view the event. Currently, this requires the cable systems to have computerized decoders in place at each customer's home. These decoders are extremely expensive. Moreover, various hardware and software must be located at the cable system head end in order to operate the decoders.
It would be advantageous to have an inexpensive device to offer customers to enable them to receive a temporary service such as a special movie, boxing match and the like for which the customer could pay for the one presentation.
The present invention overcomes the need for computerized decoders in place at each customer's home and the various hardware and software that must be at the cable system's head end to run the decoders. In addition, it provides an inexpensive device which can be coupled between the cable service and the TV monitor in the customer's home that will allow the cable output to be coupled to the TV monitor for a predetermined period of time and then the circuit opened.
In one embodiment of the invention, a switch selectively couples an input signal to a load only for a predetermined period of time established solely by the switch. This is accomplished with a time limited signal conduction circuit for selectively providing a signal path from an input to a load. The conduction circuit includes an electronically operated switch inserted between the input and the load for opening the signal path to prevent the signal from being transmitted to the load. The novel switch is DC operated from a self-contained power supply that has a predetermined power rating such that the time period of the preselected current drain from the battery can be predetermined. The battery is electrically isolated from the external inputs and outputs to the switch but it provides a bias to RF current controlled resistors, when the switch is activated, to allow an input signal to pass to the output of the switch during the time the battery maintains its charge.
In another embodiment of the invention, the device can be purchased by a user as a ticket to enable a TV monitor to receive and view a CATV program transmitted as a scrambled RFTV signal. The ticket has a housing having an input terminal for removable coupling to the RFTV cable and an output terminal for removable coupling to the TV monitor. A time limited switch and a descrambler unit are contained in the housing and are coupled between the input and the output terminals for enabling a scrambled CATV signal to be unscrambled and coupled to the TV monitor only for a time period predetermined by the time limited switch. An insulator or nonelectric conducting slab of any well-known type is inserted in the battery circuit and operable by the user to unalterably activate the time limited switch such that the scrambled RFTV signal is passed by the switch to the descrambler only for the predetermined period of time of the life of the battery, thus enabling a viewer to view a selected program that lasts for any known predetermined period of time such as a movie which may last for 2 or 21/2 hours.
Thus it is an object of the present invention to provide a time limited signal conduction circuit including an electronically operated switch inserted between a signal input and a load for opening the signal path to prevent the signal from being transmitted to the load and also having means coupled to the switch for selectively causing the switch to close the signal path only for a predetermined period of time, thereby allowing the signal to be transmitted to the load only during the predetermined time period.
It is also an object of the present invention to provide a time limited signal conduction circuit in which current controlled devices such as diodes or RF current controlled resistors are selectively biased by a self-contained power source at the option of the user to cause the diodes or RF current controlled resistors to conduct only during the time the battery has power.
It is still another object of the present invention to provide a disposable, self-contained electronic switch and descrambler system for use in a CATV system which will selectively provide a signal path that enables a purchaser of the switch to view only a selected scrambled video program.
It is yet another object of the present invention to provide a ticket for purchase by a user to enable a TV monitor to receive and view a CATV program transmitted as a scrambled RFTV signal and wherein the ticket is discarded after the program being viewed is completed.